Poster Presentation ANZOS-ASLM-ICCR 2019

Whey protein stimulates secretion of gastrointestinal peptides and lowers postprandial glycaemia, but has no effect on eating behaviour in overweight women: a beverage study. (#192)

Jia Jiet Mr Lim 1 2 , Ivana Dr Sequeira 1 3 , Wilson Mr Yip 1 3 , Louise Dr Lu 1 3 , Sally Prof Poppitt 1 2 3
  1. Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland, New Zealand
  2. Riddet Centre of Research Excellence (CoRE), Palmerston North, New Zealand
  3. High Value Nutrition Metabolic Health Programme, Auckland, New Zealand

Background: Although a high-protein diet stimulates the secretion of gastrointestinal (GI) peptides and lowers postprandial glycaemia, the hypothesis that protein-induced satiety is regulated by GI peptides, in particular glucagon-like peptide-1 (GLP-1) and Peptide YY (PYY) remains under debate. This study investigated the dose-response relationship between protein intake, postprandial change in GI peptides, glycaemia and eating behaviour.

Design: 24 overweight women received a 380mL whey protein beverage containing either 0g protein (control; 0 kJ), 12.5g protein (low protein, LP; 210 kJ) or 50.0g protein (high protein, HP; 846 kJ) as a preload breakfast on 3  occasions in a randomised, crossover design. Subjective feelings of appetite were measured using Visual Analogue Scales (VAS) and blood samples were collected over 4 hours post-preload. Subsequently, participants received an outcome lunch meal and were instructed to eat ad libitum (freely) until comfortably full. Energy intake (EI) was recorded.

Results: HP significantly increased postprandial circulating insulin, glucagon and GLP-1, and lowered glycaemia (all, preload * time, p < 0.01). Postprandial PYY was consistently higher after HP when compared to control (preload, p < 0.01), but with no significant increase throughout the postprandial period (preload * time, p > 0.05). HP did not significantly change VAS ratings of hunger, fullness, thoughts of food or satisfaction over 4 hours relative to LP or control  (all, preload * time, p > 0.05). Unexpectedly, despite the high protein and energy content of the HP preload, there was no difference in ad lib EI between the 3 beverages (mean ± SEM, control: 3047 ± 314kJ; LP: 2945 ± 225kJ; HP: 2961 ± 259kJ; p > 0.05).

Conclusion: Despite the significant increase in circulating GI peptides following HP beverage, there was no evidence that this in turn resulted in a change in eating behaviour.